After you successfully extract the contents of hrj01217518rar , you will see one or more files or folders. Before executing any program ( *.exe , *.msi , *.bat ), repeat your malware scan on the extracted items.
Another thought: could this be part of a steganography challenge? Sometimes, codes are hidden within images or files, and breaking them requires understanding the components. If the code is broken into parts referring to an aircraft and a file format, maybe the solution involves researching both elements. For example, finding historical references to the Harris Reconnaissance Jet (HRJ) and associating it with a RAR archive from a specific date (the numbers 01217518 perhaps indicating a date or time code). hrj01217518rar